#### • Class 11 Physics Demo

Explore Related Concepts

# Basic Physics Formula Sheet

In this section, we will briefly discus some basic physics formulae. Let us start with Newton’s law of motion. Newton’s first law of motion states that if an object is in resting state, it will remain in the same until any unbalanced force acts on it. Likewise an object under motion will maintain its speed and direction until an unbalanced force acts upon it. The second law of motion is given by following formula:

F = $\frac{dp}{dt}$ or F = ma (since p = mv)

Here “F” is the force applied on an object, “p” is the momentum of the object, “$\frac{dp}{dt}$”   is rate of change in momentum of object per unit time, “m” is mass of the object and “a” is acceleration of object.

Hence according to the above formula, Newton’s second law states that the rate of change in momentum of an object is proportional to the force applied on the object. Since both force and acceleration are vector quantities; direction of force vector and that of acceleration vector is same.  And hence the direction of rate of change in momentum of the object is also the same as that of the force vector.

The impulse formula is given as:

Impulse = FΔ t = Δ p

Hence impulse is measurement of product of force and time which in turn is equals to the change in momentum of the object.

The Newton’s third law of motion is given by following formula:

FAB = - FBA
The above formula states that each action has an opposite and equal reaction.

The law of conservation of momentum is given by following formula:

m1u1 + m2u2 =  m1v1 + m1v2

Here “m1” is the mass of first object and “m2” is the mass of second object. And “u1” and u2” are initial velocity of those objects while v1 and v2 are final velocities. The formula states that total momentum of objects before collision is equal to the total momentum after collision; hence momentum is conserved.

The formula for work done by a force is given as following:

W= F.s

It states that work done by a force is equals to the dot product of force vector and displacement vector.

All the objects under motion have kinetic energy which is expressed by following formula:

Kinetic Energy = $\frac{1}{2}$ mv2

The net change in kinetic energy of a system denotes the net work done by the applied force. It is given by following formula:
W= K- Ki

The potential energy of an object is expressed by following formula:

dU = F. dr

Here F is the conservative force. Change in potential energy of a system is given by following formula:

Potential energy= mgh

Here “m” is mass of object, “g” is acceleration due to gravity and “h” is the distance between two points.

The mechanical energy of an object is sum of kinetic energy and potential energy. It is given by following formula:

Mechanical energy = kinetic energy + potential energy

The law of conservation of energy is given by following formula:

K1 + P1 = K2 + P2